/*++

Copyright (c) 2005 - 2006, Intel Corporation                                                         
All rights reserved. This program and the accompanying materials                          
are licensed and made available under the terms and conditions of the BSD License         
which accompanies this distribution.  The full text of the license may be found at        
http://opensource.org/licenses/bsd-license.php                                            
                                                                                          
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

Module Name:

  Ip4Input.c

Abstract:

  IP4 input process.

--*/

#include "Ip4Impl.h"

STATIC
IP4_ASSEMBLE_ENTRY *
Ip4CreateAssembleEntry (
  IN IP4_ADDR               Dst,
  IN IP4_ADDR               Src,
  IN UINT16                 Id,
  IN UINT8                  Protocol
  )
/*++

Routine Description:

  Create a empty assemble entry for the packet identified by 
  (Dst, Src, Id, Protocol). The default life for the packet is
  120 seconds.

Arguments:

  Dst       - The destination address
  Src       - The source address
  Id        - The ID field in IP header
  Protocol  - The protocol field in IP header

Returns:

  NULL if failed to allocate memory for the entry, otherwise
  the point to just created reassemble entry.

--*/
{

  IP4_ASSEMBLE_ENTRY        *Assemble;

  Assemble = NetAllocatePool (sizeof (IP4_ASSEMBLE_ENTRY));

  if (Assemble == NULL) {
    return NULL;
  }

  NetListInit (&Assemble->Link);
  NetListInit (&Assemble->Fragments);

  Assemble->Dst      = Dst;
  Assemble->Src      = Src;
  Assemble->Id       = Id;
  Assemble->Protocol = Protocol;
  Assemble->TotalLen = 0;
  Assemble->CurLen   = 0;
  Assemble->Head     = NULL;
  Assemble->Info     = NULL;
  Assemble->Life     = IP4_FRAGMENT_LIFE;

  return Assemble;
}

STATIC
VOID
Ip4FreeAssembleEntry (
  IN IP4_ASSEMBLE_ENTRY     *Assemble
  )
/*++

Routine Description:

  Release all the fragments of a packet, then free the assemble entry

Arguments:

  Assemble  - The assemble entry to free

Returns:

  None

--*/
{
  NET_LIST_ENTRY            *Entry;
  NET_LIST_ENTRY            *Next;
  NET_BUF                   *Fragment;

  NET_LIST_FOR_EACH_SAFE (Entry, Next, &Assemble->Fragments) {
    Fragment = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);

    NetListRemoveEntry (Entry);
    NetbufFree (Fragment);
  }

  NetFreePool (Assemble);
}

VOID
Ip4InitAssembleTable (
  IN IP4_ASSEMBLE_TABLE     *Table
  )
/*++

Routine Description:

  Initialize an already allocated assemble table. This is generally
  the assemble table embedded in the IP4 service instance.

Arguments:

  Table - The assemble table to initialize.

Returns:

  NONE

--*/
{
  UINT32                    Index;

  for (Index = 0; Index < IP4_ASSEMLE_HASH_SIZE; Index++) {
    NetListInit (&Table->Bucket[Index]);
  }
}

VOID
Ip4CleanAssembleTable (
  IN IP4_ASSEMBLE_TABLE     *Table
  )
/*++

Routine Description:

  Clean up the assemble table: remove all the fragments
  and assemble entries.

Arguments:

  Table - The assemble table to clean up

Returns:

  None

--*/
{
  NET_LIST_ENTRY            *Entry;
  NET_LIST_ENTRY            *Next;
  IP4_ASSEMBLE_ENTRY        *Assemble;
  UINT32                    Index;

  for (Index = 0; Index < IP4_ASSEMLE_HASH_SIZE; Index++) {
    NET_LIST_FOR_EACH_SAFE (Entry, Next, &Table->Bucket[Index]) {
      Assemble = NET_LIST_USER_STRUCT (Entry, IP4_ASSEMBLE_ENTRY, Link);

      NetListRemoveEntry (Entry);
      Ip4FreeAssembleEntry (Assemble);
    }
  }
}

STATIC
VOID
Ip4TrimPacket (
  IN NET_BUF                *Packet,
  IN INTN                   Start,
  IN INTN                   End
  )
/*++

Routine Description:

  Trim the packet to fit in [Start, End), and update the per 
  packet information.

Arguments:

  Packet  - Packet to trim
  Start   - The sequence of the first byte to fit in
  End     - One beyond the sequence of last byte to fit in.

Returns:

  None

--*/
{
  IP4_CLIP_INFO             *Info;
  INTN                      Len;

  Info = IP4_GET_CLIP_INFO (Packet);

  ASSERT (Info->Start + Info->Length == Info->End);
  ASSERT ((Info->Start < End) && (Start < Info->End));

   if (Info->Start < Start) {
    Len = Start - Info->Start;

    NetbufTrim (Packet, (UINT32) Len, NET_BUF_HEAD);
    Info->Start   = Start;
    Info->Length -= Len;
  }

  if (End < Info->End) {
    Len = End - Info->End;

    NetbufTrim (Packet, (UINT32) Len, NET_BUF_TAIL);
    Info->End     = End;
    Info->Length -= Len;
  }
}

STATIC
VOID
Ip4OnFreeFragments (
  IN VOID                   *Arg
  )
/*++

Routine Description:

  Release all the fragments of the packet. This is the callback for 
  the assembled packet's OnFree. It will free the assemble entry, 
  which in turn will free all the fragments of the packet.

Arguments:

  Arg - The assemble entry to free

Returns:

  None

--*/
{
  Ip4FreeAssembleEntry ((IP4_ASSEMBLE_ENTRY *) Arg);
}

STATIC
NET_BUF *
Ip4Reassemble (
  IN IP4_ASSEMBLE_TABLE     *Table,
  IN NET_BUF                *Packet
  )
/*++

Routine Description:

  Reassemble the IP fragments. If all the fragments of the packet
  have been received, it will wrap the packet in a net buffer then
  return it to caller. If the packet can't be assembled, NULL is
  return.

Arguments:

  Table   - The assemble table used.
  Packet  - The fragment to assemble

Returns:

  NULL if the packet can't be reassemble. The point to just assembled
  packet if all the fragments of the packet have arrived.

--*/
{
  IP4_HEAD                  *IpHead;
  IP4_CLIP_INFO             *This;
  IP4_CLIP_INFO             *Node;
  IP4_ASSEMBLE_ENTRY        *Assemble;
  NET_LIST_ENTRY            *Head;
  NET_LIST_ENTRY            *Prev;
  NET_LIST_ENTRY            *Cur;
  NET_BUF                   *Fragment;
  NET_BUF                   *NewPacket;
  INTN                      Index;

  IpHead  = Packet->Ip;
  This    = IP4_GET_CLIP_INFO (Packet);

  ASSERT (IpHead != NULL);

  //
  // First: find the related assemble entry
  //
  Assemble  = NULL;
  Index     = IP4_ASSEMBLE_HASH (IpHead->Dst, IpHead->Src, IpHead->Id, IpHead->Protocol);

  NET_LIST_FOR_EACH (Cur, &Table->Bucket[Index]) {
    Assemble = NET_LIST_USER_STRUCT (Cur, IP4_ASSEMBLE_ENTRY, Link);

    if ((Assemble->Dst == IpHead->Dst) && (Assemble->Src == IpHead->Src) &&
        (Assemble->Id == IpHead->Id)   && (Assemble->Protocol == IpHead->Protocol)) {
      break;
    }
  }
  
  //
  // Create a new assemble entry if no assemble entry is related to this packet
  //
  if (Cur == &Table->Bucket[Index]) {
    Assemble = Ip4CreateAssembleEntry (
                 IpHead->Dst,
                 IpHead->Src,
                 IpHead->Id,
                 IpHead->Protocol
                 );

    if (Assemble == NULL) {
      goto DROP;
    }

    NetListInsertHead (&Table->Bucket[Index], &Assemble->Link);
  }

  //
  // Find the point to insert the packet: before the first
  // fragment with THIS.Start < CUR.Start. the previous one
  // has PREV.Start <= THIS.Start < CUR.Start.
  //
  Head = &Assemble->Fragments;

  NET_LIST_FOR_EACH (Cur, Head) {
    Fragment = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);

    if (This->Start < IP4_GET_CLIP_INFO (Fragment)->Start) {
      break;
    }
  }
  
  //
  // Check whether the current fragment overlaps with the previous one.
  // It holds that: PREV.Start <= THIS.Start < THIS.End. Only need to
  // check whether THIS.Start < PREV.End for overlap. If two fragments
  // overlaps, trim the overlapped part off THIS fragment.
  //
  if ((Prev = Cur->ForwardLink) != Head) {
    Fragment  = NET_LIST_USER_STRUCT (Prev, NET_BUF, List);
    Node      = IP4_GET_CLIP_INFO (Fragment);

    if (This->Start < Node->End) {
      if (This->End <= Node->End) {
        NetbufFree (Packet);
        return NULL;
      }

      Ip4TrimPacket (Packet, Node->End, This->End);
    }
  }
  
  //
  // Insert the fragment into the packet. The fragment may be removed
  // from the list by the following checks.
  //
  NetListInsertBefore (Cur, &Packet->List);

  //
  // Check the packets after the insert point. It holds that:
  // THIS.Start <= NODE.Start < NODE.End. The equality holds
  // if PREV and NEXT are continuous. THIS fragment may fill
  // several holes. Remove the completely overlapped fragments
  //
  while (Cur != Head) {
    Fragment = NET_LIST_USER_STRUCT (Cur, NET_BUF, List);
    Node     = IP4_GET_CLIP_INFO (Fragment);

    //
    // Remove fragments completely overlapped by this fragment
    //
    if (Node->End <= This->End) {
      Cur = Cur->ForwardLink;

      NetListRemoveEntry (&Fragment->List);
      Assemble->CurLen -= Node->Length;

      NetbufFree (Fragment);
      continue;
    }
    
    //
    // The conditions are: THIS.Start <= NODE.Start, and THIS.End <
    // NODE.End. Two fragments overlaps if NODE.Start < THIS.End.
    // If two fragments start at the same offset, remove THIS fragment
    // because ((THIS.Start == NODE.Start) && (THIS.End < NODE.End)).
    //
    if (Node->Start < This->End) {
      if (This->Start == Node->Start) {
        NetListRemoveEntry (&Packet->List);
        goto DROP;
      }

      Ip4TrimPacket (Packet, This->Start, Node->Start);
    }

    break;
  }
  
  //
  // Update the assemble info: increase the current length. If it is
  // the frist fragment, update the packet's IP head and per packet
  // info. If it is the last fragment, update the total length.
  //
  Assemble->CurLen += This->Length;

  if (This->Start == 0) {
    //
    // Once the first fragment is enqueued, it can't be removed
    // from the fragment list. So, Assemble->Head always point
    // to valid memory area.
    //
    ASSERT (Assemble->Head == NULL);

    Assemble->Head  = IpHead;
    Assemble->Info  = IP4_GET_CLIP_INFO (Packet);
  }
  
  //
  // Don't update the length more than once.
  //
  if (IP4_LAST_FRAGMENT (IpHead->Fragment) && (Assemble->TotalLen == 0)) {
    Assemble->TotalLen = This->End;
  }
  
  //
  // Deliver the whole packet if all the fragments received.
  // All fragments received if:
  //  1. received the last one, so, the totoal length is know
  //  2. received all the data. If the last fragment on the
  //     queue ends at the total length, all data is received.
  //
  if ((Assemble->TotalLen != 0) && (Assemble->CurLen >= Assemble->TotalLen)) {

    NetListRemoveEntry (&Assemble->Link);

    //
    // If the packet is properly formated, the last fragment's End 
    // equals to the packet's total length. Otherwise, the packet 
    // is a fake, drop it now.
    //
    Fragment = NET_LIST_USER_STRUCT (Head->BackLink, NET_BUF, List);

    if (IP4_GET_CLIP_INFO (Fragment)->End != Assemble->TotalLen) {
      Ip4FreeAssembleEntry (Assemble);
      return NULL;
    }

    //
    // Wrap the packet in a net buffer then deliver it up
    //
    NewPacket = NetbufFromBufList (
                  &Assemble->Fragments,
                  0,
                  0,
                  Ip4OnFreeFragments,
                  Assemble
                  );

    if (NewPacket == NULL) {
      Ip4FreeAssembleEntry (Assemble);
      return NULL;
    }

    NewPacket->Ip                  = Assemble->Head;
    *IP4_GET_CLIP_INFO (NewPacket) = *Assemble->Info;
    return NewPacket;
  }

  return NULL;

DROP:
  NetbufFree (Packet);
  return NULL;
}

VOID
Ip4AccpetFrame (
  IN IP4_PROTOCOL           *Ip4Instance,
  IN NET_BUF                *Packet,
  IN EFI_STATUS             IoStatus,
  IN UINT32                 Flag,
  IN VOID                   *Context
  )
/*++

Routine Description:

  The IP4 input routine. It is called by the IP4_INTERFACE when a 
  IP4 fragment is received from MNP. 

Arguments:

  Ip4Instance - The IP4 child that request the receive, most like it is NULL.
  Packet      - The IP4 packet received.
  IoStatus    - The return status of receive request.
  Flag        - The link layer flag for the packet received, such as multicast.
  Context     - The IP4 service instance that own the MNP.

Returns:

  None

--*/
{
  IP4_SERVICE               *IpSb;
  IP4_CLIP_INFO             *Info;
  IP4_HEAD                  *Head;
  UINT32                    HeadLen;
  UINT32                    OptionLen;
  UINT32                    TotalLen;
  UINT16                    Checksum;

  IpSb = (IP4_SERVICE *) Context;

  if (EFI_ERROR (IoStatus) || (IpSb->State == IP4_SERVICE_DESTORY)) {
    goto DROP;
  }
  
  //
  // Check that the IP4 header is correctly formated
  //
  if (Packet->TotalSize < IP4_MIN_HEADLEN) {
    goto RESTART;
  }

  Head     = (IP4_HEAD *) NetbufGetByte (Packet, 0, NULL);
  HeadLen  = (Head->HeadLen << 2);
  TotalLen = NTOHS (Head->TotalLen);

  //
  // Mnp may deliver frame trailer sequence up, trim it off.
  //
  if (TotalLen < Packet->TotalSize) {
    NetbufTrim (Packet, Packet->TotalSize - TotalLen, FALSE);
  }

  if ((Head->Ver != 4) || (HeadLen < IP4_MIN_HEADLEN) || 
      (TotalLen < HeadLen) || (TotalLen != Packet->TotalSize)) {
    goto RESTART;
  }
  
  //
  // Some OS may send IP packets without checksum.
  //
  Checksum = ~NetblockChecksum ((UINT8 *) Head, HeadLen);

  if ((Head->Checksum != 0) && (Checksum != 0)) {
    goto RESTART;
  }

  //
  // Convert the IP header to host byte order, then get the per packet info.
  //
  Packet->Ip      = Ip4NtohHead (Head);

  Info            = IP4_GET_CLIP_INFO (Packet);
  Info->LinkFlag  = Flag;
  Info->CastType  = Ip4GetHostCast (IpSb, Head->Dst, Head->Src);
  Info->Start     = (Head->Fragment & IP4_HEAD_OFFSET_MASK) << 3;
  Info->Length    = Head->TotalLen - HeadLen;
  Info->End       = Info->Start + Info->Length;
  Info->Status    = EFI_SUCCESS;

  //
  // The packet is destinated to us if the CastType is non-zero.
  //
  if ((Info->CastType == 0) || (Info->End > IP4_MAX_PACKET_SIZE)) {
    goto RESTART;
  }

  //
  // Validate the options. Don't call the Ip4OptionIsValid if 
  // there is no option to save some CPU process.
  //
  OptionLen = HeadLen - IP4_MIN_HEADLEN;
  
  if ((OptionLen > 0) && !Ip4OptionIsValid ((UINT8 *) (Head + 1), OptionLen, TRUE)) {
    goto RESTART;
  }

  //
  // Trim the head off, after this point, the packet is headless.
  // and Packet->TotalLen == Info->Length.
  //
  NetbufTrim (Packet, HeadLen, TRUE);

  //
  // Reassemble the packet if this is a fragment. The packet is a
  // fragment if its head has MF (more fragment) set, or it starts
  // at non-zero byte.
  //
  if ((Head->Fragment & IP4_HEAD_MF_MASK) || (Info->Start != 0)) {
    //
    // Drop the fragment if DF is set but it is fragmented. Gateway 
    // need to send a type 4 destination unreache ICMP message here.
    //
    if (Head->Fragment & IP4_HEAD_DF_MASK) {
      goto RESTART;
    }
    
    //
    // The length of all but the last fragments is in the unit of 8 bytes.
    //
    if ((Head->Fragment & IP4_HEAD_MF_MASK) && (Info->Length % 8 != 0)) {
      goto RESTART;
    }

    Packet = Ip4Reassemble (&IpSb->Assemble, Packet);

    //
    // Packet assembly isn't complete, start receive more packet.
    //
    if (Packet == NULL) {
      goto RESTART;
    }
  }
  
  //
  // Packet may have been changed. Head, HeadLen, TotalLen, and
  // info must be reloaded bofore use. The ownership of the packet
  // is transfered to the packet process logic.
  //
  Head  = Packet->Ip;
  IP4_GET_CLIP_INFO (Packet)->Status = EFI_SUCCESS;

  switch (Head->Protocol) {
  case IP4_PROTO_ICMP:
    Ip4IcmpHandle (IpSb, Head, Packet);
    break;

  case IP4_PROTO_IGMP:
    Ip4IgmpHandle (IpSb, Head, Packet);
    break;

  default:
    Ip4Demultiplex (IpSb, Head, Packet);
  }

  Packet = NULL;

RESTART:
  Ip4ReceiveFrame (IpSb->DefaultInterface, NULL, Ip4AccpetFrame, IpSb);

DROP:
  if (Packet != NULL) {
    NetbufFree (Packet);
  }

  return ;
}

BOOLEAN
Ip4InstanceFrameAcceptable (
  IN IP4_PROTOCOL           *IpInstance,
  IN IP4_HEAD               *Head,
  IN NET_BUF                *Packet
  )
/*++

Routine Description:

  Check whether this IP child accepts the packet.

Arguments:

  IpInstance  - The IP child to check
  Head        - The IP header of the packet
  Packet      - The data of the packet

Returns:

  TRUE if the child wants to receive the packet, otherwise return FALSE.

--*/
{
  IP4_ICMP_ERROR_HEAD       Icmp;
  EFI_IP4_CONFIG_DATA       *Config;
  IP4_CLIP_INFO             *Info;
  UINT16                    Proto;
  UINT32                    Index;

  Config = &IpInstance->ConfigData;

  //
  // Dirty trick for the Tiano UEFI network stack implmentation. If 
  // ReceiveTimeout == -1, the receive of the packet for this instance
  // is disabled. The UEFI spec don't have such captibility. We add 
  // this to improve the performance because IP will make a copy of
  // the received packet for each accepting instance. Some IP instances
  // used by UDP/TCP only send packets, they don't wants to receive.
  //
  if (Config->ReceiveTimeout == (UINT32)(-1)) {
    return FALSE;
  }
  
  if (Config->AcceptPromiscuous) {
    return TRUE;
  }
  
  //
  // Use protocol from the IP header embedded in the ICMP error
  // message to filter, instead of ICMP itself. ICMP handle will
  // can Ip4Demultiplex to deliver ICMP errors.
  //
  Proto = Head->Protocol;

  if (Proto == IP4_PROTO_ICMP) {
    NetbufCopy (Packet, 0, sizeof (Icmp.Head), (UINT8 *) &Icmp.Head);

    if (mIcmpClass[Icmp.Head.Type].IcmpClass == ICMP_ERROR_MESSAGE) {
      if (!Config->AcceptIcmpErrors) {
        return FALSE;
      }

      NetbufCopy (Packet, 0, sizeof (Icmp), (UINT8 *) &Icmp);
      Proto = Icmp.IpHead.Protocol;
    }
  }

  //
  // Match the protocol
  //
  if (!Config->AcceptAnyProtocol && (Proto != Config->DefaultProtocol)) {
    return FALSE;
  }

  //
  // Check for broadcast, the caller has computed the packet's 
  // cast type for this child's interface.
  //
  Info = IP4_GET_CLIP_INFO (Packet);

  if (IP4_IS_BROADCAST (Info->CastType)) {
    return Config->AcceptBroadcast; 
  } 

  //
  // If it is a multicast packet, check whether we are in the group.
  //
  if (Info->CastType == IP4_MULTICAST) {
    //
    // Receive the multicast if the instance wants to receive all packets.
    //
    if (!IpInstance->ConfigData.UseDefaultAddress && (IpInstance->Interface->Ip == 0)) {
      return TRUE;
    }
    
    for (Index = 0; Index < IpInstance->GroupCount; Index++) {
      if (IpInstance->Groups[Index] == HTONL (Head->Dst)) {
        break;
      }
    }

    return (BOOLEAN)(Index < IpInstance->GroupCount);
  }

  return TRUE;
}

EFI_STATUS
Ip4InstanceEnquePacket (
  IN IP4_PROTOCOL           *IpInstance,
  IN IP4_HEAD               *Head,
  IN NET_BUF                *Packet
  )
/*++

Routine Description:

  Enqueue a shared copy of the packet to the IP4 child if the 
  packet is acceptable to it. Here the data of the packet is 
  shared, but the net buffer isn't.

Arguments:

  IpInstance  - The IP4 child to enqueue the packet to
  Head        - The IP header of the received packet
  Packet      - The data of the received packet

Returns:

  EFI_NOT_STARTED       - The IP child hasn't been configured.
  EFI_INVALID_PARAMETER - The child doesn't want to receive the packet
  EFI_OUT_OF_RESOURCES  - Failed to allocate some resource
  EFI_SUCCESS           - A shared copy the packet is enqueued to the child.

--*/
{
  IP4_CLIP_INFO             *Info;
  NET_BUF                   *Clone;

  //
  // Check whether the packet is acceptable to this instance.
  //
  if (IpInstance->State != IP4_STATE_CONFIGED) {
    return EFI_NOT_STARTED;
  }

  if (!Ip4InstanceFrameAcceptable (IpInstance, Head, Packet)) {
    return EFI_INVALID_PARAMETER;
  }
  
  //
  // Enque a shared copy of the packet.
  //
  Clone = NetbufClone (Packet);

  if (Clone == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  //
  // Set the receive time out for the assembled packet. If it expires,
  // packet will be removed from the queue.
  //
  Info        = IP4_GET_CLIP_INFO (Clone);
  Info->Life  = IP4_US_TO_SEC (IpInstance->ConfigData.ReceiveTimeout);

  NetListInsertTail (&IpInstance->Received, &Clone->List);
  return EFI_SUCCESS;
}

STATIC
VOID
EFIAPI
Ip4OnRecyclePacket (
  IN EFI_EVENT              Event,
  IN VOID                   *Context
  )
/*++

Routine Description:

  The signal handle of IP4's recycle event. It is called back
  when the upper layer release the packet.

Arguments:

  Event   - The IP4's recycle event.
  Context - The context of the handle, which is a IP4_RXDATA_WRAP

Returns:

  None

--*/
{
  IP4_RXDATA_WRAP           *Wrap;

  Wrap = (IP4_RXDATA_WRAP *) Context;

  NET_TRYLOCK (&Wrap->IpInstance->RecycleLock);
  NetListRemoveEntry (&Wrap->Link);
  NET_UNLOCK (&Wrap->IpInstance->RecycleLock);

  ASSERT (!NET_BUF_SHARED (Wrap->Packet));
  NetbufFree (Wrap->Packet);

  gBS->CloseEvent (Wrap->RxData.RecycleSignal);
  NetFreePool (Wrap);
}

IP4_RXDATA_WRAP *
Ip4WrapRxData (
  IN IP4_PROTOCOL           *IpInstance,
  IN NET_BUF                *Packet
  )
/*++

Routine Description:

  Wrap the received packet to a IP4_RXDATA_WRAP, which will be 
  delivered to the upper layer. Each IP4 child that accepts the
  packet will get a not-shared copy of the packet which is wrapped
  in the IP4_RXDATA_WRAP. The IP4_RXDATA_WRAP->RxData is passed
  to the upper layer. Upper layer will signal the recycle event in
  it when it is done with the packet.

Arguments:

  IpInstance  - The IP4 child to receive the packet
  Packet      - The packet to deliver up.

Returns:

  NULL if failed to wrap the packet, otherwise the wrapper.

--*/
{
  IP4_RXDATA_WRAP           *Wrap;
  EFI_IP4_RECEIVE_DATA      *RxData;
  EFI_STATUS                Status;

  Wrap = NetAllocatePool (IP4_RXDATA_WRAP_SIZE (Packet->BlockOpNum));

  if (Wrap == NULL) {
    return NULL;
  }

  NetListInit (&Wrap->Link);

  Wrap->IpInstance  = IpInstance;
  Wrap->Packet      = Packet;
  RxData            = &Wrap->RxData;

  NetZeroMem (&RxData->TimeStamp, sizeof (EFI_TIME));

  Status = gBS->CreateEvent (
                  EFI_EVENT_NOTIFY_SIGNAL,
                  NET_TPL_RECYCLE,
                  Ip4OnRecyclePacket,
                  Wrap,
                  &RxData->RecycleSignal
                  );

  if (EFI_ERROR (Status)) {
    NetFreePool (Wrap);
    return NULL;
  }

  ASSERT (Packet->Ip != NULL);

  //
  // The application expects a network byte order header.
  //
  RxData->HeaderLength  = (Packet->Ip->HeadLen << 2);
  RxData->Header        = (EFI_IP4_HEADER *) Ip4NtohHead (Packet->Ip);

  RxData->OptionsLength = RxData->HeaderLength - IP4_MIN_HEADLEN;
  RxData->Options       = NULL;

  if (RxData->OptionsLength != 0) {
    RxData->Options = (VOID *) (RxData->Header + 1);
  }

  RxData->DataLength  = Packet->TotalSize;

  //
  // Build the fragment table to be delivered up.
  //
  RxData->FragmentCount = Packet->BlockOpNum;
  NetbufBuildExt (Packet, (NET_FRAGMENT *) RxData->FragmentTable, &RxData->FragmentCount);

  return Wrap;
}

EFI_STATUS
Ip4InstanceDeliverPacket (
  IN IP4_PROTOCOL           *IpInstance
  )
/*++

Routine Description:

  Deliver the received packets to upper layer if there are both received 
  requests and enqueued packets. If the enqueued packet is shared, it will
  duplicate it to a non-shared packet, release the shared packet, then 
  deliver the non-shared packet up. 

Arguments:

  IpInstance  - The IP child to deliver the packet up.

Returns:

  EFI_OUT_OF_RESOURCES - Failed to allocate resources to deliver the packets.
  EFI_SUCCESS          - All the enqueued packets that can be delivered 
                         are delivered up.

--*/
{
  EFI_IP4_COMPLETION_TOKEN  *Token;
  IP4_RXDATA_WRAP           *Wrap;
  NET_BUF                   *Packet;
  NET_BUF                   *Dup;
  UINT8                     *Head;

  //
  // Deliver a packet if there are both a packet and a receive token.
  //
  while (!NetListIsEmpty (&IpInstance->Received) && 
         !NetMapIsEmpty (&IpInstance->RxTokens)) {

    Packet = NET_LIST_HEAD (&IpInstance->Received, NET_BUF, List);

    if (!NET_BUF_SHARED (Packet)) {
      //
      // If this is the only instance that wants the packet, wrap it up.
      //
      Wrap = Ip4WrapRxData (IpInstance, Packet);

      if (Wrap == NULL) {
        return EFI_OUT_OF_RESOURCES;
      }

      NetListRemoveEntry (&Packet->List);

    } else {
      //
      // Create a duplicated packet if this packet is shared
      //
      Dup = NetbufDuplicate (Packet, NULL, IP4_MAX_HEADLEN);

      if (Dup == NULL) {
        return EFI_OUT_OF_RESOURCES;
      }
      
      //
      // Copy the IP head over. The packet to deliver up is
      // headless. Trim the head off after copy. The IP head
      // may be not continuous before the data.
      //
      Head    = NetbufAllocSpace (Dup, IP4_MAX_HEADLEN, NET_BUF_HEAD);
      Dup->Ip = (IP4_HEAD *) Head;
      
      NetCopyMem (Head, Packet->Ip, Packet->Ip->HeadLen << 2);
      NetbufTrim (Dup, IP4_MAX_HEADLEN, TRUE);

      Wrap = Ip4WrapRxData (IpInstance, Dup);

      if (Wrap == NULL) {
        NetbufFree (Dup);
        return EFI_OUT_OF_RESOURCES;
      }

      NetListRemoveEntry (&Packet->List);
      NetbufFree (Packet);

      Packet = Dup;
    }

    //
    // Insert it into the delivered packet, then get a user's
    // receive token, pass the wrapped packet up.
    //
    NET_TRYLOCK (&IpInstance->RecycleLock);
    NetListInsertHead (&IpInstance->Delivered, &Wrap->Link);
    NET_UNLOCK (&IpInstance->RecycleLock);

    Token                = NetMapRemoveHead (&IpInstance->RxTokens, NULL);
    Token->Status        = IP4_GET_CLIP_INFO (Packet)->Status;
    Token->Packet.RxData = &Wrap->RxData;

    gBS->SignalEvent (Token->Event);
  }

  return EFI_SUCCESS;
}

INTN
Ip4InterfaceEnquePacket (
  IN IP4_SERVICE            *IpSb,
  IN IP4_HEAD               *Head,
  IN NET_BUF                *Packet,
  IN IP4_INTERFACE          *IpIf
  )
/*++

Routine Description:

  Enqueue a received packet to all the IP children that share 
  the same interface.
  
Arguments:

  IpSb    - The IP4 service instance that receive the packet
  Head    - The header of the received packet
  Packet  - The data of the received packet
  IpIf    - The interface to enqueue the packet to

Returns:

  The number of the IP4 children that accepts the packet

--*/
{
  IP4_PROTOCOL              *IpInstance;
  IP4_CLIP_INFO             *Info;
  NET_LIST_ENTRY            *Entry;
  INTN                      Enqueued;
  INTN                      LocalType;
  INTN                      SavedType;

  //
  // First, check that the packet is acceptable to this interface
  // and find the local cast type for the interface. A packet sent
  // to say 192.168.1.1 should NOT be delliever to 10.0.0.1 unless
  // promiscuous receiving.
  //
  LocalType = 0;
  Info      = IP4_GET_CLIP_INFO (Packet);

  if ((Info->CastType == IP4_MULTICAST) || (Info->CastType == IP4_LOCAL_BROADCAST)) {  
    //
    // If the CastType is multicast, don't need to filter against
    // the group address here, Ip4InstanceFrameAcceptable will do
    // that later.
    //
    LocalType = Info->CastType;
    
  } else {
    //
    // Check the destination againist local IP. If the station 
    // address is 0.0.0.0, it means receiving all the IP destined 
    // to local non-zero IP. Otherwise, it is necessary to compare
    // the destination to the interface's IP address. 
    //
    if (IpIf->Ip == IP4_ALLZERO_ADDRESS) {
      LocalType = IP4_LOCAL_HOST;   
      
    } else {
      LocalType = Ip4GetNetCast (Head->Dst, IpIf);

      if ((LocalType == 0) && IpIf->PromiscRecv) {
        LocalType = IP4_PROMISCUOUS;
      }
    }
  }

  if (LocalType == 0) {
    return 0;
  }

  //
  // Iterate through the ip instances on the interface, enqueue
  // the packet if filter passed. Save the original cast type, 
  // and pass the local cast type to the IP children on the 
  // interface. The global cast type will be restored later.
  //
  SavedType       = Info->CastType;
  Info->CastType  = LocalType;

  Enqueued        = 0;

  NET_LIST_FOR_EACH (Entry, &IpIf->IpInstances) {
    IpInstance = NET_LIST_USER_STRUCT (Entry, IP4_PROTOCOL, AddrLink);
    NET_CHECK_SIGNATURE (IpInstance, IP4_PROTOCOL_SIGNATURE);

    if (Ip4InstanceEnquePacket (IpInstance, Head, Packet) == EFI_SUCCESS) {
      Enqueued++;
    }
  }

  Info->CastType = SavedType;
  return Enqueued;
}

EFI_STATUS
Ip4InterfaceDeliverPacket (
  IN IP4_SERVICE            *IpSb,
  IN IP4_INTERFACE          *IpIf
  )
/*++

Routine Description:

  Deliver the packet for each IP4 child on the interface.

Arguments:

  IpSb  - The IP4 service instance that received the packet
  IpIf  - The IP4 interface to deliver the packet.

Returns:

  EFI_SUCCESS - It always returns EFI_SUCCESS now

--*/
{
  IP4_PROTOCOL              *Ip4Instance;
  NET_LIST_ENTRY            *Entry;

  NET_LIST_FOR_EACH (Entry, &IpIf->IpInstances) {
    Ip4Instance = NET_LIST_USER_STRUCT (Entry, IP4_PROTOCOL, AddrLink);
    Ip4InstanceDeliverPacket (Ip4Instance);
  }

  return EFI_SUCCESS;
}

EFI_STATUS
Ip4Demultiplex (
  IN IP4_SERVICE            *IpSb,
  IN IP4_HEAD               *Head,
  IN NET_BUF                *Packet
  )
/*++

Routine Description:

  Demultiple the packet. the packet delivery is processed in two
  passes. The first pass will enque a shared copy of the packet
  to each IP4 child that accepts the packet. The second pass will
  deliver a non-shared copy of the packet to each IP4 child that 
  has pending receive requests. Data is copied if more than one 
  child wants to consume the packet bacause each IP child need 
  its own copy of the packet to make changes.

Arguments:

  IpSb    - The IP4 service instance that received the packet
  Head    - The header of the received packet
  Packet  - The data of the received packet

Returns:

  EFI_NOT_FOUND - No IP child accepts the packet 
  EFI_SUCCESS   - The packet is enqueued or delivered to some IP children.

--*/
{
  NET_LIST_ENTRY            *Entry;
  IP4_INTERFACE             *IpIf;
  INTN                      Enqueued;

  //
  // Two pass delivery: first, enque a shared copy of the packet
  // to each instance that accept the packet.
  //
  Enqueued = 0;

  NET_LIST_FOR_EACH (Entry, &IpSb->Interfaces) {
    IpIf = NET_LIST_USER_STRUCT (Entry, IP4_INTERFACE, Link);

    if (IpIf->Configured) {
      Enqueued += Ip4InterfaceEnquePacket (IpSb, Head, Packet, IpIf);
    }  
  }
  
  //
  // Second: deliver a duplicate of the packet to each instance.
  // Release the local reference first, so that the last instance
  // getting the packet will not copy the data.
  //
  NetbufFree (Packet);

  if (Enqueued == 0) {
    return EFI_NOT_FOUND;
  }

  NET_LIST_FOR_EACH (Entry, &IpSb->Interfaces) {
    IpIf = NET_LIST_USER_STRUCT (Entry, IP4_INTERFACE, Link);

    if (IpIf->Configured) {
      Ip4InterfaceDeliverPacket (IpSb, IpIf);
    }
  }

  return EFI_SUCCESS;
}

VOID
Ip4PacketTimerTicking (
  IN IP4_SERVICE            *IpSb
  )
/*++

Routine Description:

  Timeout the fragment and enqueued packets.

Arguments:

  IpSb  - The IP4 service instance to timeout

Returns:

  None

--*/
{
  NET_LIST_ENTRY            *InstanceEntry;
  NET_LIST_ENTRY            *Entry;
  NET_LIST_ENTRY            *Next;
  IP4_PROTOCOL              *IpInstance;
  IP4_ASSEMBLE_ENTRY        *Assemble;
  NET_BUF                   *Packet;
  IP4_CLIP_INFO             *Info;
  UINT32                    Index;

  //
  // First, time out the fragments. The packet's life is counting down
  // once the first-arrived fragment was received.
  //
  for (Index = 0; Index < IP4_ASSEMLE_HASH_SIZE; Index++) {
    NET_LIST_FOR_EACH_SAFE (Entry, Next, &IpSb->Assemble.Bucket[Index]) {
      Assemble = NET_LIST_USER_STRUCT (Entry, IP4_ASSEMBLE_ENTRY, Link);

      if ((Assemble->Life > 0) && (--Assemble->Life == 0)) {
        NetListRemoveEntry (Entry);
        Ip4FreeAssembleEntry (Assemble);
      }
    }
  }

  NET_LIST_FOR_EACH (InstanceEntry, &IpSb->Children) {
    IpInstance = NET_LIST_USER_STRUCT (InstanceEntry, IP4_PROTOCOL, Link);

    //
    // Second, time out the assembled packets enqueued on each IP child.
    //
    NET_LIST_FOR_EACH_SAFE (Entry, Next, &IpInstance->Received) {
      Packet = NET_LIST_USER_STRUCT (Entry, NET_BUF, List);
      Info   = IP4_GET_CLIP_INFO (Packet);

      if ((Info->Life > 0) && (--Info->Life == 0)) {
        NetListRemoveEntry (Entry);
        NetbufFree (Packet);
      }
    }
    
    //
    // Third: time out the transmitted packets.
    //
    NetMapIterate (&IpInstance->TxTokens, Ip4SentPacketTicking, NULL);
  }
}
